This invention relates to hook connectors mounted on the shanks of fishhooks for the attachment of lines, leaders or snells. As such, the invention will be hereinafter called a `hook connector` or a `connector` and the attached line, leader or snell will be called a `line`.
The present invention is a development from and an improvement over the hook connectors disclosed in my prior patents, U.S. Pat. Nos. 3,717,907; 3,898,760; 3,988,852 and 4,165,578. The improved hook connector and the prior art hook connectors of the reference patents are generally formed as elongated rod-like members of a hard but resilient synthetic resin material such as nylon. The shank of a hook is embedded and tightly affixed in a socket at one end of a connector. An axial passageway through the other end of the connector member has a pocket-shaped side exit near the center of the member. A line is threaded through this passageway with its end projecting from the side exit. This projecting end is knotted and the line is pulled from the connector to pull the end knot into the pocketed side exit. With the knot tightly fitting in the socket, the line is secured to the hook.
When market tests of the prior art hook connectors were under way it was discovered that the connectors would occasionally break apart at the pocketed side exit. It was also found that the line would break at the knot at a pull substantially less than the tensile strength of the line. The prior art connectors were made of the best high strength nylon or celcon materials available and in tensile tests the connectors were found to have considerable strength, even more than that of a line connected to them. The reasons for hook connector breakage, at comparatively low tension when in use were not clear. Flaws which would come about in manufacture of the connectors would be apparent in tensile tests. Other factors, the effects of aging, of sunlight and of repeated immersion in water were found to be insignificant.
It was discovered, however, that repeated connections and disconnections of a hook to a line caused some of these failures. Whenever a hook was repeatedly attached to and disconnected from the line, and the knotted end of the line was pulled into and from the pocketed side exit of the connector, the pressure of the knot could create stress concentrations and zones of weakness leading to the eventual rupture of the connector. It was also found that more often failure occurred when the knot cut itself or slipped out of itself.
An apparent solution to the connector breakage problem would be to beef up the connector by increasing its diameter. However, such was found to render the fishhook bulky and resistant to threading bait onto the hook. Also, the connector would be so rigid that the knot would not easily lock into position and be gripped by a flexing of the connector about the pocket, nor would this beefing-up of the connector solve the problem of nicks and dents in the connector which would lead to breakage.